JP2008231537A - Electrolysis simulation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exactly simulate the transient change of the temperature of an electrolytic cell without performing intricate calculation. <P>SOLUTION: The electrolysis simulation apparatus includes; a resistance value calculation means which calculates the resistance value of each electrolytic cell from the temperature of each electrolytic cell and resistance value model data; a current value calculation means which calculates a current value from the resistance value of each electrolytic cell and the current value of each electrolytic cell; a calorific power calculation means which calculates a calorific power from the current value of each electrolytic cell and the calorific power model data; an electrolyzed product abundance calculation means which calculates the abundance of the electrolyzed product from the current value of each electrolytic cell and the electrolyzed product abundance model data; a dissipation heating value calculation means which calculates the dissipation heating value based on the electrolyzed product abundance and the supply rate of an electrolytic solution; a temperature calculation means which calculates the temperature of each electrolytic cell based on the raw material supply heating value, the dissipation heating value, and the calorific power; and a temperature correction means which corrects the temperature based on the amount of heat exchange of a heat exchanger. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrolysis simulation apparatus, an electrolysis simulation method, and a program for simulating an electrolytic cell used in the production of an electrolysis product, and more specifically, electrolysis of an electrolyte solution in a plurality of electrolysis cells to produce an electrolysis product. The present invention relates to an electrolysis simulation apparatus, an electrolysis simulation method, and a program for accurately simulating a transient change in the temperature of an electrolytic cell without complicated calculation when the total current value or the like is changed during manufacturing.

In ion exchange membrane method alkaline chloride electrolysis, an ion exchange membrane method electrolytic cell is generally used as an electrolytic cell, and this electrolytic cell has an ion exchange membrane made of organic material sandwiched between an anode and chlorine and a strong strong acid. A negative atmosphere and a strong alkaline solution is present on the cathode side. For example, in an electrolytic cell filled with an aqueous solution of sodium chloride (NaCl), chlorine (Cl ₂ ) is generated on the anode side, and hydrogen (H ₂ ) and caustic soda (NaOH) are generated on the cathode side.

The amount of electrolysis product produced in the electrolytic cell is related to the current efficiency, and this current efficiency is based on the fact that the amount of electrolysis used in the electrolysis reaction is effectively utilized, that is, what percentage of the flowed electrons It is used as an index for judging whether the reaction has progressed. For example, in the above-described alkali chloride electrolysis, this current efficiency is divided into a hydrogen gas standard, a chlorine gas standard, and a caustic soda standard. The current efficiency is calculated based on the ratio of the actual production amount to the theoretical production amount of caustic soda as shown in the equation (1).
Current efficiency (%) = Caustic soda actual production ÷ Caustic soda theoretical production x 100 (1)
The current efficiency is affected by operating conditions such as raw material concentration and electrolytic membrane characteristics. In particular, the electrolytic membrane characteristics change with the usage time of the membrane. For example, the resistance value of the electrolytic membrane in the electrolytic cell is a function of the temperature of the electrolyte solution. Therefore, when producing an electrolysis product by electrolyzing the electrolyte solution, the temperature of the electrolyte solution is one of important parameters.

  In Patent Document 1, as a method for adjusting the temperature of the electrolytic cell, the current upper limit value and the lower limit value with respect to the average value of the current value of the electrolytic cell current flowing through each electrolytic cell, and the electrolytic cell temperature upper limit value are set. Set the upper limit value for the electrolyzer of the electrolyzer that has the maximum resistance value, and energize the electrolyzers other than the maximum resistance electrolyzer so that the maximum temperature is within the range of the current upper limit value and the current lower limit value. A temperature control method has been proposed. In this method, it is preferable to adjust the temperature of each electrolytic cell as high as possible within a range that does not exceed the upper temperature limit value of the electrolytic cell, and the temperature of the electrolytic cell is a heat exchanger provided in each electrolytic cell. The temperature is adjusted by cooling or overheating the electrolytic cell.

JP 2005-194564 A

  However, it is necessary to consider current efficiency and electrolytic membrane characteristics when determining the production amount of electrolytic products as described above in an electrolytic plant for producing caustic soda, and increase or decrease the production amount of electrolytic products in actual operation. In order to set the parameters such as the current value in anticipation of the changing temperature of the electrolytic cell, it is necessary to perform a complicated calculation taking into account the current efficiency and electrolytic membrane characteristics. In addition, the degree of change in current value and resistance value varies depending on the degree of temperature change, and further temperature change occurs due to the change in current value and resistance value, so it is not easy to predict the details of this temperature change. The part that relied on years of experience was great.

  The present invention has been made paying attention to the above circumstances, and in the case of changing the total current value and the like when electrolyzing an electrolytic solution in a plurality of electrolytic cells to produce an electrolysis product, the electrolytic cell It is an object of the present invention to provide an electrolysis simulation apparatus, an electrolysis simulation method, and a program for accurately simulating a transient change in temperature without performing complicated calculations.

  In order to achieve the above-described object, a simulation apparatus according to the present invention includes a DC power source that outputs a DC current while changing an output voltage so that the output current is constant, and an electrical parallel to the DC power source. Two or more electrolytic cells connected to each other, a heat exchanger for keeping the temperature of each electrolytic cell constant, and a supply means for supplying an electrolytic solution to each electrolytic cell at a predetermined temperature, An electrolysis simulation apparatus for simulating the temperature of an electrolysis apparatus for producing an electrolysis product by energizing a direct current from the power source to each electrolysis tank and electrolyzing the electrolyte solution supplied to each electrolysis tank , Resistance value model data indicating a resistance value with respect to a temperature deviation in each of the electrolytic cells, a heating value model data indicating a heating value with respect to a current value, and generation amounts of each electrolysis product with respect to the current value Storage means for storing the generated electrolysis product generation amount model data, resistance value calculating means for calculating the resistance value of each electrolytic cell from the temperature and resistance value model data of each electrolytic cell, and each electrolytic cell A current value calculating means for calculating a current value of each electrolytic cell from a resistance value and a current value of a direct current output from the DC power source; and each electrolytic cell from the current value of each electrolytic cell and the calorific value model data. A calorific value calculation means for calculating the calorific value of the tank, and an electrolysis product generation amount calculation means for calculating the electrolysis product generation quantity from the current value of each electrolytic cell and the electrolysis product generation quantity model data, respectively. And a dissipated heat amount calculating means for calculating a heat dissipation amount of each electrolytic cell based on the generated amount of the electrolysis product and the supply amount of the electrolyte solution, and supply of the electrolyte solution supplied by the supply means. Temperature correction means for correcting the temperature of each electrolytic cell based on the amount of heat, the amount of heat dissipated, and the temperature of each electrolytic cell based on the amount of heat generated, and the amount of heat exchange of the heat exchanger Means.

  In order to solve the above-described problems, a simulation method according to the present invention includes a DC power source that outputs a DC current while changing an output voltage so that the output current is constant, Two or more electrolytic cells connected in parallel to each other, a heat exchanger for keeping the temperature of each electrolytic cell constant, and a supply means for supplying an electrolytic solution to each electrolytic cell at a predetermined temperature, Simulate the temperature change of the electrolytic cell of the electrolysis apparatus that produces an electrolysis product by electrolyzing the electrolytic solution supplied to each electrolytic cell by supplying a direct current from the direct current power source to each electrolytic cell. In the electrolysis simulation method, resistance value model data indicating a resistance value with respect to temperature deviation in each of the electrolytic cells, a heat value model data indicating a heat value with respect to a current value, and each electrolysis product with respect to a current value. A storage step of storing electrolysis product generation amount model data indicating the generation amount of a product, a resistance value calculation step of calculating a resistance value of each electrolytic cell from the temperature of each electrolytic cell and the resistance value model data, A current value calculating step of calculating a current value of each electrolytic cell from a resistance value of each electrolytic cell and a current value of a direct current power source output from the direct current power source; a current value of each electrolytic cell and a calorific value model; A calorific value calculating step for calculating the calorific value of each electrolytic cell from the data; and an electrolysis for calculating the generated amount of the electrolytic product from the current value of the electrolytic cell and the electrolytic product generated amount model data, respectively. A product generation amount calculating step, a dissipated heat amount calculating step for calculating a dissipated heat amount of each electrolytic cell based on the electrolysis product generation amount and the supply amount of the electrolyte solution, and the above A temperature calculating step for calculating the temperature of each electrolytic cell based on the supply heat amount of the electrolyte solution supplied by the supply means, the dissipated heat amount, and the heat generation amount, and the heat exchange amount of the heat exchanger, And a temperature correction step for correcting the temperature of each electrolytic cell.

  In order to solve the above-described problem, a simulation program according to the present invention includes a DC power source that outputs a DC current while changing an output voltage so that the output current is constant, Two or more electrolytic cells connected in parallel to each other, a heat exchanger for keeping the temperature of each electrolytic cell constant, and a supply means for supplying an electrolytic solution to each electrolytic cell at a predetermined temperature, Simulate the temperature change of the electrolytic cell of the electrolysis apparatus that produces an electrolysis product by electrolyzing the electrolytic solution supplied to each electrolytic cell by supplying a direct current from the direct current power source to each electrolytic cell. In a computer program for causing a computer system to execute electrolysis simulation processing, resistance value model data indicating a resistance value with respect to a temperature deviation in each of the electrolytic cells, and a current value A storage step for storing calorific value model data indicating the calorific value with respect to the current value, and electrolysis product generation amount model data indicating the generation amount of each electrolysis product with respect to the current value; temperature of each electrolytic cell; and the resistance value model The current value of each electrolytic cell is calculated from the resistance value calculating step for calculating the resistance value of each electrolytic cell from the data, and the resistance value of each electrolytic cell and the current value of the DC power source output from the DC power source. A current value calculating step; a calorific value calculating step for calculating a calorific value of each electrolytic cell from the current value of each electrolytic cell and the calorific value model data; a current value of each electrolytic cell and generation of an electrolysis product A step of calculating the amount of electrolysis product generated to calculate the amount of electrolysis product generated from the quantity model data, and the amount of electrolysis product generated and the supply amount of the electrolyte solution. Based on the heat dissipation calculation step for calculating the heat dissipation amount of each electrolytic cell, the supply heat amount of the electrolyte solution supplied by the supply means, the heat dissipation amount, and the heat generation amount, the temperature of each electrolytic cell is calculated. And a temperature correction step for correcting the temperature of each electrolytic cell based on the heat exchange amount of the heat exchanger.

  According to the present invention, through a simulation using model data, it is possible to accurately simulate the dynamic behavior, particularly the temperature change over time, when electrolyzing an electrolyte solution in an electrolytic cell to produce an electrolysis product. it can. Therefore, it can also be used for training for predicting new operating conditions of the electrolytic cell.

  Hereinafter, specific embodiments to which the present invention is applied will be described with reference to the drawings. First, an example of the electrolysis apparatus in the present embodiment will be described with reference to FIG.

  FIG. 1 is a schematic diagram illustrating an example of an electrolysis apparatus. The electrolyzer 1 includes a power supply device 2 that outputs a direct current, an electrolyzer 3 (electrolyzer 3a to 3d) that electrolyzes an electrolyte solution, and a temperature set value output device 4 that outputs an electrolyzer temperature set value. And a temperature adjusting device 5 (temperature adjusting device 5a to 5d) for adjusting the temperature of the electrolytic cell to a set value, a heat exchanger (not shown), an electrolysis product outlet, and a raw material supply unit. The Further, the electrolysis apparatus 1 generates an electrolysis product in the electrolytic cell 3. For example, when an aqueous sodium chloride solution is electrolyzed by the electrolyzer 1, hydrogen, chlorine, caustic soda, fresh salt water and the like are generated as electrolysis products. The electrolysis product is not limited to this example. The electrolyzer 1 also includes a temperature set value output device 4 configured by, for example, a computer. The electrolytic cell temperature set value is output from the temperature set value output device 4 and sent to the temperature adjusting device 5.

The power supply device 2 includes a constant current device that outputs a direct current with a constant output current. This constant current device keeps the total current value supplied to the electrolytic cell 3 at a certain constant value. In the case of constant current electrolysis, the total current value I is calculated by the equation (2).
I = S × ΣI (2)
Here, ΣI is the total current density for each ion, S is the electrode area, and when the electrode area S is considered constant, the total current density for each ion is a constant value.

  The output current of the direct current output from the power supply device 2 is controlled to be constant by changing the output voltage in accordance with the change in the resistance value. The output current is appropriately selected according to the production rate of the target electrolysis product.

  The electrolytic cells 3a to 3d generate electrolysis products. Each of the electrolytic cells 3a to 3d includes an anode, a cathode, an ion exchange membrane for isolating the anode and the cathode, and a temperature adjusting device 5a to a temperature adjusting device 5d. An electrolytic solution used in the electrolytic cell 3, for example, a sodium chloride aqueous solution, is filled in the electrolytic cell 3. As the electrolytic cell 3, one that is usually manufactured with the same structure and the same standard is used. As a mode of the electrolytic cell of the electrolytic cell 3, an ion exchange membrane method electrolytic cell including an electrode and an ion exchange membrane may be mentioned. The number of electrolytic cells in the electrolytic cell 3 is not particularly limited as long as it is 2 or more. However, in the present invention, the number of electrolytic cells is preferably 3 or more, more preferably 5 or more, and usually 10 or less. Degree. In addition, the electrolytic cell 3 preferably has a resistance value in a range of ± 10% with respect to the average value when measured at the same temperature. Here, the average value is obtained by dividing the sum of the resistance of the electrolytic cell 3 measured at the same temperature by the number of electrolytic cells. The electrolytic cell 3 is electrically connected to the power supply device 2 in parallel.

In order to electrolyze the electrolytic solution in the electrolytic cell 3, the sum of the practical electrolytic voltage determined by the electrolytic cell 3, the resistance value of the electrolytic cell 3, and the load voltage obtained by the product of the current value passed through the electrolytic cell 3. It is necessary to apply a voltage equal to. Here, the practical electrolysis voltage varies depending on the method of the electrolytic cell 3, the electrode plate used in the electrolytic cell 3, the ion exchange membrane, the type and concentration of the electrolytic solution used, and the like. The resistance value of the electrolytic cell 3 varies depending on the method of the electrolytic cell 3, the electrode area, the type of electrolyte solution used, the concentration thereof, and the like. Moreover, since the electrolytic cell 3 is electrically connected mutually in parallel, the voltage applied to the electrolytic cell 3 becomes equal to the output voltage from the power supply device 2, and Formula (3) is materialized.
V = V ₀ + V _i (3)
Here, V ₀ is a practical electrolysis voltage, V _i is a load voltage, and V is an output voltage.

  By applying a direct current to the electrolytic cell 3, the electrolyte solution filled in the electrolytic cell 3 is electrolyzed, and the target electrolysis product is obtained. For example, when an aqueous sodium chloride solution is electrolyzed in the electrolytic cell 3, chlorine is generated by an oxidation reaction on the anode side, and hydrogen and caustic soda are generated by a reduction reaction on the cathode side. Since the amount of the electrolyte solution filled in the electrolytic cell 3 is kept constant by the overflow type structure, even if the current setting value is changed stepwise in the electrolysis apparatus 1, Temperature indicates a first order lag type response with a certain response time. That is, when the current setting value is changed stepwise in the electrolyzer 1, the temperature of the electrolytic cell 3 does not increase or decrease rapidly, but it is possible to accurately grasp the temporal change of this temperature by simulation. Can do.

  The temperature set value output device 4 is a device that outputs the electrolytic cell temperature set value to the temperature adjusting device 5, and is configured by a computer, for example.

  The temperature adjustment device 5 (temperature adjustment device 5a to temperature adjustment device 5d) is a device that receives an electrolytic cell temperature setting value from the outside, for example, and adjusts the electrolytic cell temperature of the electrolytic cell 3 to be this temperature setting value. is there. The temperature adjusting device 5 usually adjusts the temperature of the electrolytic cell to a set value by cooling the electrolytic cell 3 in which electrolytic heat is generated by a heat exchanger. This heat exchanger is a device that transfers heat from a high-temperature fluid to a low-temperature fluid across a heat transfer wall, and the structure can be selected from double pipe, multi-tube type, cascade type, coil type, etc. As a heat exchange method, an arbitrary method can be selected from a countercurrent method, a parallel flow method, a cross flow method, and the like. Further, the temperature adjusting device 5 is configured so that the temperature of the electrolytic cell becomes a set value by heating the electrolytic cell 3 with a heat exchanger immediately after the start of operation of the electrolyzer 1 or when the generation of electrolytic heat is small. adjust.

  The electrolysis product outlet is a portion provided for taking out the electrolysis product generated in the electrolytic cell 3 from the electrolysis cell 3. Normally, the electrolysis product is provided near the top and bottom of the electrolysis cell 3. Is provided. For example, in an electrolysis product generated when an aqueous sodium chloride solution is electrolyzed in the electrolytic cell 3, hydrogen gas is extracted from the cathode side vapor phase outlet, and chlorine gas is extracted from the anode side vapor phase outlet. Caustic soda can be taken out from a take-out port provided in the cathode side liquid phase part, and fresh salt water can be taken out from a take-out port provided in the anode side liquid phase part to a storage tank or the like connected to the outside. Note that the shape of the electrolysis product outlet can be arbitrarily selected from a circular shape, a polygonal shape, and the like.

  The raw material supply unit is a device that supplies an electrolyte solution for filling the electrolytic cell 3, and can control the flow rate and temperature of the raw material.

  Next, the configuration of the electrolytic simulation apparatus will be described, and then the operation method of each configuration will be described in detail. Here, for example, an electrolysis simulation is assumed in the case where an aqueous solution of sodium chloride is electrolyzed in the electrolytic cell 3 to generate an electrolysis product.

  FIG. 2 is a diagram showing functional blocks of the electrolytic simulation apparatus according to the present embodiment.

  The electrolysis simulation apparatus 6 includes an input unit 7 for performing an input for executing a simulation connected via a bus 17, a processing unit 8 for executing a simulation operation, and various model data and programs necessary for the simulation. It comprises a memory 9 for storing, an output unit 16 for outputting simulation results, and the like.

  The input unit 7 relates to control conditions for simulating an electrolysis apparatus such as a set temperature, an electrolyte temperature in an initial state, a set potential, a set current, the number of calculations, a raw material supply amount, and a heat exchange amount in a heat exchanger. Data is input, and the input unit 7 supplies the input data to the memory 9 and the processing unit 8 via the bus 17.

  The processing unit 8 includes a calculation unit and a determination unit (not shown). The calculation unit reads various model data (to be described later) stored in the memory 9 from data input to the input unit 7, and selects selected model data. Is executed based on a simulation program 15 including various calculation formulas stored in the memory 9. The determination unit analyzes various model data stored in the memory 9 and compares the model data with the actual value, and determines a calculation process according to the comparison result.

  The memory 9 stores model data and the like necessary for executing the simulation. The memory 9 has, for example, resistance value model data 10 indicating the resistance value of the electrolytic cell 3 based on the temperature deviation of the electrolytic cell 3, and the amount of heat generated in the electrolytic cell 3 according to the amount of current passed through the electrolytic cell 3. The amount of generated heat model data 11 indicating hydrogen generation amount model data 12 for analyzing the amount of hydrogen generated in the electrolytic cell 3 according to the amount of current supplied to the electrolytic cell 3, and the amount of current applied to the electrolytic cell 3 Chlorine generation model data 13 for analyzing the chlorine generation amount generated in the electrolytic cell 3, and caustic soda generation model data 14 for analyzing the caustic generation amount generated in the electrolytic cell 3 in accordance with the amount of current supplied to the electrolytic cell 3. , And a simulation program 15 including a program for performing various calculation formulas and temperature adjustment used when performing computations in the computation unit. In addition, various model data stored in the memory 9 are updated as needed through the input unit 7 for operation data for about one month immediately before the simulation execution, thereby calculating errors caused by electrolytic membrane characteristics in the electrolytic cell 3. For example, it is possible to minimize a calculation error due to a change in the resistance value of the electrolytic cell accompanying the deterioration of the electrolytic membrane. The various model data update methods may be performed by other methods without using the input unit 7.

  The output unit 16 outputs simulation results based on various model data stored in the memory 9 calculated by the processing unit 8.

  Next, details of the processing unit 8 will be described with reference to FIG. FIG. 3 is a diagram illustrating a functional block configuration of the processing unit 8.

  The resistance value calculation unit 18 calculates the resistance value of the electrolytic cell 3 based on the temperature of the electrolytic cell 3 and the resistance value model data 10 stored in the memory 9.

FIG. 4 is a diagram illustrating an example of the correlation between the temperature deviation and the resistance value in the resistance value model data 10. This resistance value model data 10 is y = −0.016x + 0.913 (R ² = 0.9560), where the x axis is the temperature deviation (° C.) in the electrolytic cell and the y axis is the rated resistance value (%). And has a negative first-order correlation. Therefore, the resistance value calculation unit 18 can accurately calculate the resistance value corresponding to the temperature of the electrolytic cell 3 based on the resistance value model data 10. Note that the model data shown in the present embodiment is an example as described above, and is not limited to these model data. For example, the data distribution may have a second-order or higher correlation. The temperature deviation refers to the temperature based on the arithmetic average value of each electrolytic cell temperature during the model data collection period. The rated% refers to the long-time rated value of the constant current source, that is, the constant current source is continuous. In this case, the maximum value of the supply current amount that guarantees the life of the apparatus is 100%, and the supply current amount zero is 0%.

  The current value calculation unit 19 calculates the current value of the electrolytic cell 3 based on the resistance value of the electrolytic cell 3 calculated by the resistance value calculation unit 18. The current value calculation unit 19 can calculate each current value of the electrolytic cell 3 by distributing the total amount of current flowing through the electrolytic cell 3. For example, the current value calculation unit 19 can calculate the ohmic value from the simulation program 15 stored in the memory 9. The current value of the electrolytic cell 3 is calculated using the law.

  The calorific value calculation unit 20 calculates the calorific value generated in the electrolytic cell 3 from the current value of the electrolytic cell 3 calculated by the current value calculation unit 19 based on the calorific value model data 11 stored in the memory 9. .

FIG. 5 is a diagram showing an example of the correlation between the electrolytic current value and the heat generation amount in the heat generation amount model data 11. The calorific value model data 11 is represented by an approximate expression of y = 0.9903x (R ² = 0.9920), where the x-axis is the rated current value (%) and the y-axis is the rated calorific value (%). And has a positive first order correlation. Therefore, the calorific value calculation unit 20 can accurately calculate the calorific value generated in the electrolytic cell 3 based on the calorific value model data 11.

  The dissipated heat amount calculation unit 21 calculates the amount of electrolysis product generated in the electrolytic cell 3 and the mass of the supplied raw material from the amount of current in the electrolytic cell 3 calculated by the current value calculation unit 19. Calculate the amount of heat dissipated.

  The dissipated heat amount calculation unit 21 calculates the generation amount of the electrolysis product, that is, the hydrogen generation amount calculation unit 22 that calculates the generation amount of hydrogen, the chlorine generation amount calculation unit 23 that calculates the generation amount of chlorine, and the generation amount of caustic soda. It comprises a caustic soda generation amount calculation unit 24 to calculate and a fresh salt water generation amount calculation unit 25 to calculate the generation amount of fresh salt water, and calculates the amount of heat dissipated by the electrolysis products generated from the electrolytic cell 3. Details of the simulation procedure in the heat dissipation amount calculation unit 21 will be described with reference to the flowchart of FIG.

  In step S 1, the hydrogen generation amount calculation unit 22, the chlorine generation amount calculation unit 23, and the caustic soda generation amount calculation unit 24 are stored in the memory 9 from the current value of the electrolytic cell 3 calculated by the current value calculation unit 19. Based on the hydrogen generation amount model data 12, the chlorine generation amount model data 13, and the caustic soda generation amount model data 14, the generation amounts of hydrogen gas, chlorine gas, and caustic soda generated in the electrolytic cell 3 are calculated.

FIG. 7 is a diagram showing an example of the correlation between the electrolysis current value and the hydrogen generation amount in the hydrogen generation amount model data 12. This hydrogen generation amount model data 12 is an approximate expression of y = 0.9797x (R ² = 0.8983) where the x-axis is the rated current value (%) and the y-axis is the rated hydrogen generation amount (%). And has a positive first-order correlation. Therefore, the hydrogen generation amount calculation unit 22 can accurately calculate the hydrogen generation amount in the electrolytic cell 3 based on the hydrogen generation amount model data 12.

FIG. 8 is a diagram showing an example of the correlation between the electrolysis current value and the chlorine generation amount in the chlorine generation amount model data 13. This chlorine generation amount model data 13 is an approximate expression of y = 0.9929x (R ² = 0.9997) where the x-axis is the rated current value (%) and the y-axis is the rated chlorine generation amount (%). And has a positive first-order correlation. Therefore, the chlorine generation amount calculation unit 23 can accurately calculate the chlorine generation amount in the electrolytic cell 3 based on the chlorine generation amount model data 13.

FIG. 9 is a diagram showing an example of the correlation between the electrolytic current value and the caustic soda generation amount in the caustic soda generation model data 14. This caustic soda generation model data 14 is an approximate expression of y = 0.9702x (R ² = 0.9795) where the x-axis is the rated current value (%) and the y-axis is the rated caustic generation amount (%). And has a positive first-order correlation. Therefore, the caustic soda generation amount calculation unit 24 can accurately calculate the caustic soda generation amount in the electrolytic cell 3 based on the chlorine generation amount model data 13.

  In step S <b> 2, the fresh salt water generation amount calculation unit 25 calculates the fresh salt water according to the formula (4) based on the generation amounts of the hydrogen gas, chlorine gas, and caustic soda described above, and the raw material supply amount from the raw material supply unit (not shown). Calculate the amount of generation.

Amount of fresh salt water = Amount of raw material supplied-Total amount of generated gas (hydrogen gas, chlorine gas)-Amount of caustic soda generated (4)
In step S3, the dissipated heat amount calculation unit 21 calculates the generation amount of hydrogen gas, chlorine gas, caustic soda, and fresh salt water calculated in step S1 and step S2 based on the simulation program 15 stored in the memory 9 (5). The amount of heat dissipated from the electrolytic cell 3 is calculated from the specific heat of each product substance.
C = mc (5)
Here, C represents the heat capacity of each product material, m represents the mass of each product material, and c represents the specific heat of each product material. Through the processes in steps S1 to S3 described above, the heat dissipation amount calculation unit 21 calculates the heat dissipation amount.

  The electrolytic cell temperature calculation unit 26 is a heat generation amount calculated by the heat generation amount calculation unit 20, a generated heat amount in the electrolytic cell 3 calculated by the dissipated heat amount calculation unit 21, and a raw material carry-in heat amount calculation unit 27 (not shown). A balance calculation with the negative heat amount derived from the electrolyte solution supplied from the raw material supply unit is performed, and the electrolytic cell temperature is calculated in consideration of the heat amount contributing to the temperature change of the electrolytic cell 3.

The heat transfer amount calculation unit 28 calculates the heat transfer amount heat exchanged by the heat exchanger in order to keep the electrolytic cell temperature at a constant temperature. For example, the amount of heat exchange between the electrolytic cell side and the thermal refrigerant side in a countercurrent heat exchanger is calculated by equations (6) and (7).
Q = UAΔT (6)
ΔT = (ΔT ₁ −ΔT ₂ ) / ln (ΔT ₁ / ΔT ₂ ) (7)
Here, Q is the amount of heat transfer, U is the overall heat transfer coefficient, A is the effective heat transfer area, and ΔT is the logarithm average temperature difference between the process fluid and the thermal refrigerant at the inlet / outlet of the heat exchanger. ΔT ₁ indicates the temperature difference between the process fluid and the thermal refrigerant at the process fluid inlet, and ΔT ₂ indicates the temperature difference between the process fluid and the thermal refrigerant at the process fluid outlet. The larger the temperature difference between the two fluids, the greater the transmission. The amount of heat increases. By this heat exchange, when the electrolytic cell temperature rises, it can be cooled, and when the electrolytic cell temperature falls, the flow rate of the thermal refrigerant can be adjusted and raised. In the countercurrent heat exchanger, the process fluid inlet side described above is the thermal refrigerant outlet side. Further, in the above-described equation (7), when the ratio of ΔT ₁ and ΔT ₂ is smaller than 2, ΔT can be approximated by an arithmetic average value of both temperatures.

  Further, the heat transfer amount calculation unit 28 fixes the inlet temperature of the process fluid and the thermal refrigerant, swings the temperature of the heat exchange outlet of each fluid, calculates the enthalpy change of both fluids due to heat transfer, The temperature of the heat exchange outlet of both fluids is converged and calculated so that the enthalpy change amounts of the fluids are equal. In this convergence calculation, a new heat transfer amount when the flow rate and supply temperature of both fluids change, that is, the temperature of the heat exchange outlet of each fluid, can be calculated by iteration.

  The post-heat removal electrolytic cell temperature calculation unit 29 calculates the temperature of the new electrolytic cell from the heat transfer amount heat exchanged between the electrolytic cell side and the thermal refrigerant side calculated by the heat transfer amount calculation unit 28. That is, the temperature of the new electrolytic cell is calculated by taking the difference of the heat exchange amount calculated by the heat transfer amount calculation unit 28 from the electrolytic cell temperature of the electrolytic cell 3.

  Next, a method for simulating electrolysis of the electrolyte solution in the electrolytic cell 3 described above will be described. Below, the scene at the time of performing the simulation of the temperature change in the electrolytic cell 3 is assumed.

  FIG. 10 is a flowchart for explaining the processing operation of each functional block of the processing unit 8. Although the simulation program 15 used for this processing operation is stored in the memory 9 and is interpreted and / or executed by the processing unit 8, it is needless to say that the present invention is not limited to this example.

  In step S <b> 10, the input unit 7 inputs an initial temperature of the electrolytic cell 3. The input of the initial temperature is not limited to the method input from the input unit 7.

  In step S <b> 11, the resistance value calculation unit 18 calculates the resistance value of the electrolytic cell 3 based on the resistance value model data 10 stored in the memory 9 based on the temperature of the electrolytic cell 3 input in step S <b> 10.

  In step S12, the current value calculation unit 19 calculates the current value of the electrolytic cell 3 from the resistance value and total current value of the electrolytic cell 3 calculated in step S11.

  In step S <b> 13, the calorific value calculation unit 20 calculates the calorific value generated in the electrolytic cell 3 based on the calorific value model data 11 stored in the memory 9 based on the current value of the electrolytic cell 3 calculated in step S <b> 12.

  In step S <b> 14, the electrolytic cell temperature calculation unit 26 is calculated by the calorific value generated in the electrolytic cell 3 calculated in step S <b> 13, the amount of heat carried by the raw material calculated by the raw material carry-in heat amount calculation unit 27, and the dissipated heat amount calculation unit 21. The temperature of the electrolytic cell 3 is calculated from the amount of heat dissipated.

  In step S <b> 15, the heat transfer amount calculation unit 28 calculates the heat transfer amount to be heat-exchanged in order to keep the temperature of the electrolytic cell 3 calculated in step 14 constant.

  In step S <b> 16, the heat transfer amount calculation unit 28 determines whether the temperature calculated based on the heat transfer amount has converged to a predetermined threshold value or less. If this temperature has converged below the predetermined threshold, the process proceeds to step S17. If the temperature has not converged below the predetermined threshold, the process returns to step S15 to continue the simulation of calculating the heat transfer amount for heat exchange.

  In step S17, the post-heat removal electrolytic cell temperature calculation unit 29 calculates the temperature of the electrolytic cell 3 after heat removal based on the temperature result determined by the heat transfer amount calculation unit 28 to converge in step S16. To do.

  Thus, a series of processes for simulating the temperature at a certain point in the electrolytic cell 3 is completed. The processing unit 8 can reproduce the temperature change in the actual electrolytic cell by performing a series of simulation processes in step S10 to step S17, and what kind of temperature the electrolytic cell temperature will be in the near future. Can be expected. Moreover, the process part 8 can simulate the time-dependent change of electrolytic cell temperature by performing repeatedly the series of simulation processes in step S10-step S17 periodically.

  Next, specific examples of the present invention will be described. In light of the common general knowledge in this field, it is clear that the present invention is not limited to the final conditions of the experimental conditions used in the following examples.

〔Example〕
In an electrolysis apparatus 1 as shown in FIG. 1, a predetermined number of ion-exchange membrane electrolytic cells that are produced according to the same standard and have a practical electrolysis voltage of a predetermined value are prepared, and these are electrically connected in parallel with each other at a constant current. Connected to a DC power supply. The electrolytic bath 3 was filled with a sodium chloride aqueous solution as an electrolyte solution, and a direct current was applied from the constant current direct current power supply device so that the output current became a constant value.

  FIG. 11 (A) compares the change over time in the total rated current value when the total rated current value supplied to the electrolytic cell 3 is reduced by 10% from 100% to 90% between the actual value and the simulation calculation result. Is. 11 (B) to (D) show the temperature change of the electrolytic cell 3 over time when the total rated current value is reduced by 10% as shown in FIG. 11 (A). As a representative example, the results of three tanks are shown.

  As shown in FIGS. 11B to 11D, when the current reduction as shown in FIG. 11A was performed, the results of the temperature change with time of the actual value and the simulation result almost coincided.

  As described above, according to the electrolysis simulation apparatus 6 in the present embodiment, the operation data on the dynamic behavior, particularly the temperature change involved in producing the electrolysis product by electrolyzing the electrolyte solution in the electrolytic cell. Therefore, it is possible to accurately simulate a transient change in temperature when the operation state of the electrolytic cell is changed.

  It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, the temperature change with time is set as a simulation target. However, other parameters such as the production amount may be set as the simulation target. Also, the raw material supply amount and the heat exchange amount may be input at the input unit 7 as in the case of the initial temperature.

It is a schematic diagram which shows an example of the electrolyzer in this Embodiment. It is a block diagram which shows typically the structure of the simulation apparatus in this Embodiment. It is a figure which shows the functional block structure in the calculating part of the simulation apparatus in this Embodiment. It is a figure which shows an example of the resistance value model data used for simulation. It is a figure which shows an example of the emitted-heat amount model data used for simulation. It is a flowchart for demonstrating the operation | movement procedure at the time of calculating the amount of heat dissipation in simulation. It is a figure which shows an example of the hydrogen generation amount model data used for simulation. It is a figure which shows an example of the chlorine generation amount model data used for simulation. It is a figure which shows an example of the caustic generation amount model data used for simulation. It is a flowchart for demonstrating the operation | movement procedure of the temperature simulation in this Embodiment. It is a figure which shows the time-dependent change of the total rated current value in the actual value at the time of decreasing the total rated current value of an electrolytic cell, and a simulation result.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrolysis device, 2 Power supply device, 3 Electrolysis tank, 4 Temperature set value output device, 5 Temperature adjustment device, 6 Electrolysis simulation device, 7 Input part, 8 Processing part, 9 Memory, 10 Resistance value model data, 11 Calorific value Model data, 12 Hydrogen generation amount model data, 13 Chlorine generation amount model data, 14 Caustic soda generation amount model data, 15 Simulation program, 16 Output section, 17 Bus, 18 Resistance value calculation section, 19 Current value calculation section, 20 Heat generation amount Calculation unit, 21 Dissipated heat amount calculation unit, 22 Hydrogen generation amount calculation unit, 23 Chlorine generation amount calculation unit, 24 Caustic soda generation amount calculation unit, 25 Fresh salt water generation amount calculation unit, 26 Electrolyzer temperature calculation unit, 27 Raw material carry heat amount calculation Part, 28 heat transfer amount calculation part, 29 post-heat removal electrolytic cell temperature calculation part

Claims (7)

A DC power source that outputs a DC current while changing the output voltage so that the output current is constant, two or more electrolytic cells electrically connected in parallel to the DC power source, and the temperature of each electrolytic cell And a supply means for supplying an electrolytic solution to each of the electrolytic cells at a predetermined temperature. A direct current is passed from the direct current power source to each of the electrolytic cells, In an electrolysis simulation apparatus for simulating the temperature of an electrolysis tank of an electrolysis apparatus that produces an electrolysis product by electrolyzing an electrolyte solution supplied to the tank,
Resistance value model data indicating a resistance value with respect to a temperature deviation in each of the electrolytic cells, a heat value model data indicating a heat value with respect to a current value, and an electrolysis product generation amount model indicating each amount of electrolysis product generated with respect to a current value Storage means for storing data;
Resistance value calculating means for calculating the resistance value of each electrolytic cell from the temperature of each electrolytic cell and the resistance value model data;
Current value calculating means for calculating a current value of each electrolytic cell from a resistance value of each electrolytic cell and a current value of a direct current output from the DC power source;
A calorific value calculating means for calculating the calorific value of each electrolytic cell from the current value of each electrolytic cell and the calorific value model data;
An electrolysis product generation amount calculating means for calculating the electrolysis product generation amount from the current value of each electrolytic cell and the electrolysis product generation amount model data;
Dissipated heat amount calculating means for calculating the heat dissipation amount of each electrolytic cell based on the amount of electrolysis product generated and the amount of electrolyte solution supplied;
Temperature calculation means for calculating the temperature of each electrolytic cell based on the amount of heat supplied by the electrolyte solution supplied by the supply means, the amount of heat dissipated, and the amount of heat generated;
An electrolysis simulation apparatus comprising: temperature correction means for correcting the temperature of each electrolytic cell based on the heat exchange amount of the heat exchanger.   2. The electrolysis simulation apparatus according to claim 1, wherein the temperature correction means calculates the heat transfer amount of the heat exchange amount and takes a difference of the heat transfer calculation result from each of the electrolytic cell temperatures.   At least one parameter among the initial temperature of each electrolytic cell, the current value of the DC power source output from the DC power source, the supply amount of the electrolyte solution supplied from the supply means, and the heat exchange amount of the heat exchanger The electrolysis simulation apparatus according to claim 1, further comprising an input unit for inputting.   2. The electrolytic simulation apparatus according to claim 1, wherein the electrolyte solution contains sodium chloride, and hydrogen, chlorine, caustic soda, and fresh salt water are generated as the electrolysis product.   2. The electrolysis simulation apparatus according to claim 1, wherein each of the model data is represented by a primary correlation equation. A DC power source that outputs a DC current while changing the output voltage so that the output current is constant, two or more electrolytic cells electrically connected in parallel to the DC power source, and the temperature of each electrolytic cell And a supply means for supplying an electrolytic solution to each of the electrolytic cells at a predetermined temperature. A direct current is passed from the direct current power source to each of the electrolytic cells, In an electrolysis simulation method for simulating a temperature change of an electrolysis tank of an electrolysis apparatus for producing an electrolysis product by electrolyzing an electrolyte solution supplied to the tank,
Resistance value model data indicating a resistance value with respect to temperature deviation in each of the electrolytic cells, a heat value model data indicating a heat value with respect to a current value, and an electrolysis product generation amount indicating a generation amount of each electrolysis product with respect to the current value A storage step for storing model data;
A resistance value calculating step for calculating the resistance value of each electrolytic cell from the temperature of each electrolytic cell and the resistance value model data;
A current value calculating step of calculating a current value of each electrolytic cell from a resistance value of each electrolytic cell and a current value of a DC power source output from the DC power source;
A calorific value calculating step for calculating the calorific value of each electrolytic cell from the current value of each electrolytic cell and the calorific value model data;
An electrolysis product generation amount calculating step for calculating the generation amount of the electrolysis product from the current value of each electrolytic cell and the electrolysis product generation amount model data;
A heat dissipation amount calculation step for calculating the heat dissipation amount of each electrolytic cell based on the amount of electrolysis product generated and the amount of electrolyte solution supplied;
A temperature calculating step for calculating the temperature of each electrolytic cell based on the supply heat amount of the electrolyte solution supplied by the supply means, the dissipated heat amount, and the heat generation amount;
A temperature correction step for correcting the temperature of each electrolytic cell based on the heat exchange amount of the heat exchanger. A DC power source that outputs a DC current while changing the output voltage so that the output current is constant, two or more electrolytic cells electrically connected in parallel to the DC power source, and the temperature of each electrolytic cell And a supply means for supplying an electrolytic solution to each of the electrolytic cells at a predetermined temperature. A direct current is passed from the direct current power source to each of the electrolytic cells, In a program for causing a computer system to execute an electrolysis simulation process for simulating a temperature change of an electrolysis tank of an electrolysis apparatus for producing an electrolysis product by electrolyzing an electrolyte solution supplied to the tank,
Resistance value model data indicating a resistance value with respect to temperature deviation in each of the electrolytic cells, a heat value model data indicating a heat value with respect to a current value, and an electrolysis product generation amount indicating a generation amount of each electrolysis product with respect to the current value A storage step for storing model data;
A resistance value calculating step for calculating the resistance value of each electrolytic cell from the temperature of each electrolytic cell and the resistance value model data;
A current value calculating step of calculating a current value of each electrolytic cell from a resistance value of each electrolytic cell and a current value of a DC power source output from the DC power source;
A calorific value calculating step for calculating the calorific value of each electrolytic cell from the current value of each electrolytic cell and the calorific value model data;
An electrolysis product generation amount calculating step for calculating the generation amount of the electrolysis product from the current value of each electrolytic cell and the electrolysis product generation amount model data;
A heat dissipation amount calculation step for calculating the heat dissipation amount of each electrolytic cell based on the amount of electrolysis product generated and the amount of electrolyte solution supplied;
A temperature calculating step for calculating the temperature of each electrolytic cell based on the supply heat amount of the electrolyte solution supplied by the supply means, the dissipated heat amount, and the heat generation amount;
A temperature correction step for correcting the temperature of each electrolytic cell based on the heat exchange amount of the heat exchanger.

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